java上传文件以流方式判断类型

public enum FileType {
	/**
	 * JEPG.
	 */
	JPEG("FFD8FF"),

	/**
	 * PNG.
	 */
	PNG("89504E47"),

	/**
	 * GIF.
	 */
	GIF("47494638"),

	/**
	 * TIFF.
	 */
	TIFF("49492A00"),

	/**
	 * Windows Bitmap.
	 */
	BMP("424D"),

	/**
	 * CAD.
	 */
	DWG("41433130"),

	/**
	 * Adobe Photoshop.
	 */
	PSD("38425053"),

	/**
	 * Rich Text Format.
	 */
	RTF("7B5C727466"),

	/**
	 * XML.
	 */
	XML("3C3F786D6C"),

	/**
	 * HTML.
	 */
	HTML("68746D6C3E"),
	/**
	 * CSS.
	 */
	CSS("48544D4C207B0D0A0942"),
	/**
	 * JS.
	 */
    JS("696B2E71623D696B2E71"),
	/**
	 * Email [thorough only].
	 */
	EML("44656C69766572792D646174653A"),

	/**
	 * Outlook Express.
	 */
	DBX("CFAD12FEC5FD746F"),

	/**
	 * Outlook (pst).
	 */
	PST("2142444E"),

	/**
	 * MS Word/Excel.
	 */
	XLS_DOC("D0CF11E0"), XLSX_DOCX("504B030414000600080000002100"),
	/**
	 * Visio
	 */
	VSD("d0cf11e0a1b11ae10000"),
	/**
	 * MS Access.
	 */
	MDB("5374616E64617264204A"),
	/**
	 * WPS文字wps、表格et、演示dps都是一样的
	 */
	WPS("d0cf11e0a1b11ae10000"),
	/**
	 * torrent
	 */
	TORRENT("6431303A637265617465"),
	/**
	 * WordPerfect.
	 */
	WPD("FF575043"),

	/**
	 * Postscript.
	 */
	EPS("252150532D41646F6265"),

	/**
	 * Adobe Acrobat.
	 */
	PDF("255044462D312E"),

	/**
	 * Quicken.
	 */
	QDF("AC9EBD8F"),

	/**
	 * Windows Password.
	 */
	PWL("E3828596"),

	/**
	 * ZIP Archive.
	 */
	ZIP("504B0304"),

	/**
	 * RAR Archive.
	 */
	RAR("52617221"),
	/**
	 * JSP Archive.
	 */
	JSP("3C2540207061676520"),
	/**
	 * JAVA Archive.
	 */
	JAVA("7061636B61676520"),
	/**
	 * CLASS Archive.
	 */
	CLASS("CAFEBABE0000002E00"),
	/**
	 * JAR Archive.
	 */
	JAR("504B03040A000000"),
	/**
	 * MF Archive.
	 */
	MF("4D616E69666573742D56"),
	/**
	 *EXE Archive.
	 */
	EXE("4D5A9000030000000400"),
	/**
	 *CHM Archive.
	 */
	CHM("49545346030000006000"),
	/*
	 * INI("235468697320636F6E66"), SQL("494E5345525420494E54"), BAT(
	 * "406563686F206f66660D"), GZ("1F8B0800000000000000"), PROPERTIES(
	 * "6C6F67346A2E726F6F74"), MXP(
	 * "04000000010000001300"),
	 */
	/**
	 * Wave.
	 */
	WAV("57415645"),

	/**
	 * AVI.
	 */
	AVI("41564920"),

	/**
	 * Real Audio.
	 */
	RAM("2E7261FD"),

	/**
	 * Real Media.
	 */
	RM("2E524D46"),

	/**
	 * MPEG (mpg).
	 */
	MPG("000001BA"),

	/**
	 * Quicktime.
	 */
	MOV("6D6F6F76"),

	/**
	 * Windows Media.
	 */
	ASF("3026B2758E66CF11"),

	/**
	 * MIDI.
	 */
	MID("4D546864"),
	/**
	 * MP4.
	 */
	MP4("00000020667479706d70"),
	/**
	 * MP3.
	 */
	MP3("49443303000000002176"),
	/**
	 * FLV.
	 */
	FLV("464C5601050000000900");
	private String value = "";

	/**
	 * Constructor.
	 * 
	 * @param type
	 */
	private FileType(String value) {
		this.value = value;
	}

	public String getValue() {
		return value;
	}

	public void setValue(String value) {
		this.value = value;
	}

}

public final class FileTypeJudge {
/** * Constructor */
private FileTypeJudge() {}
/** * 将文件头转换成16进制字符串 * * @param 原生byte * @return 16进制字符串 */
private static String bytesToHexString(byte[] src) {
StringBuilder stringBuilder = new StringBuilder();
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
return stringBuilder.toString();
}
/** * 得到文件头 * * @param filePath * 文件路径 * @return 文件头 * @throws IOException */
private static String getFileContent(String filePath) throws IOException {
byte[] b = new byte[28];
InputStream inputStream = null;
try {
inputStream = new FileInputStream(filePath);
inputStream.read(b, 0, 28);
} catch (IOException e) {
e.printStackTrace();
throw e;}
finally {if (inputStream != null)
{
try {inputStream.close();} 
catch (IOException e) 
{e.printStackTrace();throw e;}}}
return bytesToHexString(b);}
/** * 判断文件类型 * * @param filePath * 文件路径 * @return 文件类型 */
public static FileType getType(String filePath) throws IOException {
String fileHead = getFileContent(filePath);
if (fileHead == null || fileHead.length() == 0) {
return null;}fileHead = fileHead.toUpperCase();
FileType[] fileTypes = FileType.values();
for (FileType type : fileTypes) {
if (fileHead.startsWith(type.getValue())) {
return type;}}return null;}
public static void main(String args[]) throws Exception {
System.out.println(FileTypeJudge.getType("d:\\FileMonitor.java"));
}
}

参考:http://www.cnblogs.com/live365wang/archive/2011/03/24/1993744.html

http://www.cnblogs.com/rainsilence/archive/2012/06/06/2538294.html